There were a number of issues in upgrading the project, but I can't figure out how to get past this one:
[!] CocoaPods could not find compatible versions for pod "video_player_avfoundation":
In Podfile:
video_player_avfoundation (from .symlinks/plugins/video_player_avfoundation/darwin
)
Specs satisfying the video_player_avfoundation (from
.symlinks/plugins/video_player_avfoundation/darwin)
dependency were found, but they required a higher minimum deployment target.